I checked my Student Office (circa 2007). Within a document, there is a very colorful block way to the right, and at the top labeled "Change Styles". It has a couple of large uppercase A's inside the block. That will let you change font and typefaces. It also gives you a drop menu with "Set as Default". I didn't explore it, but if you can adapt this to your version, it might be just what you need.
On presentations; if you actually read the script, 14 or 16 point type is very good. I've also found that setting an 8 1/2 X 11 sheet into two newspaper columns can be helpful. I haven't done this since WordPerfect 3.0 was the hot tip in word processing.